Letermovir, as a novel anti cytomegalovirus (CMV) drug, has shown significant efficacy in preventing CMV infection after hematopoietic stem cell transplantation. Its unique mechanism of action and good safety make it an important clinical choice.

1 Clinical efficacy data

(1) Preventive effect: In phase III clinical trials, the incidence of CMV infection was significantly reduced compared to placebo (37.5% vs 60.6% within 24 weeks after transplantation).

(2) Virus suppression: Maintaining activity against clinical isolates of CMV resistant to ganciclovir/valganciclovir.

(3) Treatment advantages: significantly reduce adverse reactions such as bone marrow suppression compared to traditional drugs.

2. Characteristics of the mechanism of action

(1) Unique target: works by inhibiting the CMVDNA termination enzyme complex.

(2) High selectivity: does not affect human DNA polymerase, and has good safety.

(3) Synergistic effect: Can be used in combination with existing anti CMV drugs.

3 Special Population Effects

(1) Transplant patients: significantly reduce the risk of CMV reactivation in allogeneic hematopoietic stem cell transplant recipients.

(2) Renal insufficiency: No need to adjust dosage, efficacy is not affected.

(3) Abnormal liver function: Patients with mild to moderate damage can still use it safely.

4. Regular medication time

(1) Standard recommendation: Take orally once a day at a fixed time, preferably in the morning or evening when it is easy to remember, and maintain a 24-hour dosing interval.

(2) Transplant patients: After hematopoietic stem cell transplantation, medication usually needs to be continued until 100 days after surgery. It is recommended to set a daily medication alarm to avoid omissions.

5. Relationship with diet

(1) Food impact: It can be taken with or without food, but high-fat meals may delay absorption. It is recommended to maintain consistency in medication.

(2) Special diet: Avoid taking grapefruit/juice together as it may inhibit CYP3A metabolic enzymes and cause abnormal increases in blood drug concentration.

6 Medication precautions

(1) Best timing: It is recommended to start prophylactic medication before transplantation.

(2) Treatment control: The standard prevention period is 100 days after transplantation.

(3) Monitoring indicators: Regular testing of CMVDNA load and liver function is required.